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Belle II/Superkekb: New Physics and the Next Generation Tom Browder, University of Hawai’I at Manoa

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Belle II/Superkekb: New Physics and the Next Generation Tom Browder, University of Hawai’I at Manoa Belle II/SuperKEKB: New Physics and the Next Generation Tom Browder, University of Hawai’i at Manoa Introduction, History and Motivation: What’s happening in high energy physics ? Some Highlights from First Collisions and the Phase 2 Belle II Pilot Run. The complex superconducting final focus is partially visible here (before closing the endcap). Physics and the Road Ahead to Phase 3, the first Physics run Vertex detector before Conclusion; opportunities installation for Vietnam The Geography of the International Belle II collaboration Belle II now has grown to ~800 researchers from 26 countries This is rather unique in Japan and Asia. The only comparable example is the T2K experiment at JPARC, which is also an international collaboration Including one very good one from Vietnam, Dong Van Thanh Youth and potential: There are ~267 graduate students in the collaboration What is happening these days in high energy physics ? (Personal perspective, based on trips to international conferences and summer schools.) Typical scenes in Hanoi, Vietnam NY Times on Aug 5, 2016 2016: US Some other media Belle II headlines on ICHEP: summer school, “Physicists look to @PNNL in the future as new Richland, particle dream dies” Washington “Particle Physics in Mourning” “The End of the Beginning” Friday August 5, 2016 at ICHEP in Chicago, the ATLAS and CMS collaborations announced that the 750 GeV di-photon excess had disappeared in the large Run II 13 TeV dataset. 2017 US Belle II School@Ole Miss New York Times, June 19, 2017 But since then, the silence from the energy frontier has been ominous. “The feeling in the field is at best one of confusion and at worst depression,” Adam Falkowski, a particle physicist at the Laboratoire de Physique Théorique d’Orsay in France, wrote recently in an article for the science journal Inference. “These are difficult times for the theorists,” Gian Giudice, the head of CERN’s theory department, said. “Our hopes seem to have been shattered. We have not found what we wanted.” Summer 2018 1200 international participants. LHC High pt: Expected Standard Model (SM) t-tbar-Higgs coupling observed by CMS and ATLAS, SM Higgsb bbar evidence found, no SUSY (SUperSYmmetric) or extra particles. Dark Matter: No dark matter (DM) signals in Xenon 1T or other leading DM experiments (i.e. DEAP(Canada), LUX (US), PandaX (China)) Neutrinos: Sterile neutrinos at reactors disfavored by Daya Bay results. Planck only needs 3 neutrinos for the CMB (Cosmic Microwave Background). Hints of a normal hierarchy for neutrino masses at NoVa at Fermilab. This is not what the theorists told us to expect ! US Belle II summer school July 2018, Cincinnati, Ohio “Not found: Any evidence for additional particles. There's no sugar-coating this one: this was perhaps the greatest hope of most physicists. New particles at scales between 100 GeV and ~2 TeV were sorely hoped for, and at various times, some statistically suggestive evidence emerged for a few candidates. Unfortunately, with more and better data, this tentative evidence evaporated, and now, with Run I and Run II complete, there are not even any good suggestions of where such a new particle might be. That means it's important to try new things, including general searches, says Gian Giudice, who heads CERN’s theory department and is not involved in any of the Remain Calm, Do not Panic ! experiments. “This is the right approach, at this point.” (Scientific American, Aug 2018) Stay calm. Don’t panic !! The intensity frontier will save you (again) as it has done many times in the past. (KLμμ, B + - + - mixing, AFB(e e μ μ ), Electroweak corrections etc…) Beauty and the Beast The legend is reborn Quantum Mechanical (QM) Finesse versus Brute Force Energy conservation ? Banking Analogy (may be easier to understand): At the Heisenberg Quantum Mechanical bank, customers with no collateral may take out billion Euro loans if they return the full loan within a billionth of a second. If a beautiful but rare customer takes out such huge loans very frequently, the bank will take notice. Looks odd (or asymmetric) in the bank’s special full length mirror. N.B. Sometimes it is much better to have a large collateral Werner Heisenberg, and pay back the loan directly after a longer time. Physicist and QM banker Time-dependent CP violation is “A Double-Slit experiment” with particles and antiparticles QM interference between two diagrams box diagram + tree diagram tree diagram Vtd b c J/ψ b t d d KS c + s s K c d d S d t b c J/ψ Vtd Measures the phase of the Vtd weak interaction coupling constant or equivalently the phase of Bd –anti Bd mixing. 10 0 Measurement of sin(2φ1)/sin(2β) in BCharmonium K modes 0 (cc)K B S B 0 J/ψKS J/ψKL J/ψKL 1 1 sin2φ 1=0.667±0.023±0.012 sin2φ1=0.687±0.028±0.012 Af=0.006±0.016±0.012 Af=-0.024±0.020±0.016 PRL108,171802 (2012) PRD79,072009 (2009) Overpowering evidence for CP violation (matter-antimatter asymmetries). >>>> The phase of Vtd is in good agreement with Standard Model expectations.11 This is the phase of Bd mixing. 2008: Critical Role of the B factories in Japan and the US in the verification of the Kobayashi- Maskawa hypothesis was recognized and cited by the Nobel Foundation A single irreducible phase accounts for all the matter-antimatter asymmetries in particle physics. CP violating effects in the B sector are O(1) rather than O(10-3) as in the kaon system. CP Violation is now included in most of the undergraduate particle physics textbooks. I will skip the comic book or manga explanation of CP violation. I will also not cover the famous And I will gloss over competition/r the critical role of ace between the original Belle Belle and experiment in the BaBar to 2008 Nobel Prize for discover CP Kobayashi and violation in Maskawa. the b-sector in 2001. Sorry this manga is all males. 2015: “Missing Energy Decays” of the B meson New Frontier: Start of a NP program that will last a decade or more15. Standard Quantum Model 3-D Mechanical Billiard Table. Lepton Billiards g Experimentally good for leptonic decays t = 1.0000 ± 0.0014 g to an accuracy much better than 1%. m G(K - ® m -n) To the 1% level, - - @ 1 G(K ® e n) But what about semi-leptonic decays of beauty ? τ Now can access the e 3rd generation of leptons and couple to quarks ! Does that make a difference ? Unexpected competition from Belle LHCb@CERN Summer 2018 ICHEP: World Average is still ~4σ from the Standard Model SM B(B ® D(*)tn) R(D(*) ) = B(B ® D(*)ln) The neutral BEH boson is now firmly established by experimental results from ATLAS and CMS. Now planning for future Higgs flavor factory facilities . (e.g ILC, HL-LHC, CEPC, FCC). N.B. SM has no charged Higgs PGU Question: What do these acronyms stand for ? Does the GP (Brout- Englert-Higgs particle) have a “brother” i.e. the charged Higgs ? PGU Question: How would the LHC observe a charged Higgs ? Y. Nambu, 1921-2015 Measurements at Belle II and direct searches at hadron colliders take complementary approaches. N.B. Leptoquarks are also possible. 20 Complementarity of e+ e- and LHC The current combined Bτυ limit places a stronger constraint than direct searches from LHC exps. for the next few years. 1 ab-1 Belle II Currently inclusive bsγ rules 2 out mH+ below ~480 GeV/c range at 95% CL (independent of This region is allowed tanβ), M. Misiak et al. (assuming no other NP) http://arxiv.org/abs/1503.01789 21 Science Magazine Red Hot Flavor Physics The stakes are getting higher Science Magazine, April 20, 2017 Back to the SM More QM Leptonic Flavor Billiards billiard table BF(B ® K (*)m +m - ) R (q2 ) = K (*) BF(B ® K (*)e+e- ) For experts: q2= M2(l+l-) Experts: Angular correlations in BK* l l also show deviations from the SM, 4-5σ R is ~2.6σ from the SM K RK* ~2.1σ (low bin), 2.5σ (central bin) “Light DM” sensitivity in e+e-γ+nothing This is hard. Requires a special new trigger that is being developed for Belle II. Should be tested during Phase III in 2019. 24 “Light DM” sensitivity in γ+nothing 25 The world is waiting January 2018 for our results. https://www.nature.com/articles/d41586-018-00162-x SuperKEKB, the first new collider in particle physics since the LHC in 2008 (electron-positron (e+e-) rather than proton-proton (pp)) Some items to note: 1) Brand-new positron damping ring (commissioned spring 2018). 2) New 3 km positron ring vacuum chamber (commissioned in 2016). Optics and vacuum scrubbing this spring. 3) New complex superconducting final focus (commissioned this spring 2018). SuperKEKB/Belle II Luminosity Profile Belle/KEKB recorded ~1000 fb-1 . Now have to change units on y-axis to ab-1 Beam currents only a factor of two higher than KEKB (~PEPII) “nano-beams” are the key; vertical beam size is 50nm at the IP N.B. To realize this steep turn-on, requires close cooperation between Belle II and SuperKEKB [and some international collaboration on the accelerator, including the US and Europe]. Vietnam: The old 1 ab-1 Belle dataset can be analyzed by Belle II collaborators. Some Belle II jargon Phase 1: Simple background commissioning detector (diodes, diamonds TPCs, crystals…). No final focus. Only single beam background studies possible [started in Feb 2016 and completed in June 2016.
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